Aka no Ex
by darksider82
Summary: Mephisto had an agenda of his own in the form of the Red Exorcist
1. Chapter 1

Aka no Ex  
Red Exorcist  
Blue Exorcist/Harry Potter crossover

 **Darksider82  
Anyone**

 **Ein: Aka no Ex**

Dumbledore stared as Fudge's teacher screeched and raged at the old Headmaster for he had forbidden her to use Blood Quills on students and he had overturned all of the detentions she had laid against Harry Potter.

"HOW DARE YOU! YOU ONLY RUN THIS SCHOOL BECAUSE THE MINISTER ALLOWS IT!"

Harry groaned as he sat in one of Dumbledore's rather comfortable chairs in the corner of the room wearing a short sleeved shirt revealing some intricate birthmarks coloured black rather like tattoo's in the form of claws just finishing above his wrists. The marks made their way down his back forming the outline of wings and down the back of his legs they formed something Harry could only describe as a tail.

The marks had always been a faded red on his pale skin since as far as he could remember and ever since his first year at Hogwarts when he had incinerated Quirrell the marks had become darker and now they were two to three shades off pure black.

"Why am I here Headmaster? Considering you've not spoken to me at all this year." Growled Harry his eyes flashing red as he noticed small flying cat heads and bacteria tails floating around the office. He had never seen them inside the school before.

Suddenly klaxons began to wail "Umbridge...What did you do?" Growled Harry standing up sharply, causing the toad like professor to turn a toady eyes and sickly sweet voice to him.

"You...will...sit...down... ...As...You're...in...deep...trouble." She stated slowly as if talking to a little boy; she never noticed the massive ghost like corpse of her cat emerge from the shadows of the office. Dumbledore did and he opened a draw in his desk.

"Umbridge GET DOWN!" Screamed Harry tackling the toad like professor to the floor as a massive claw gouged a three inch cut into the magically saturated floor of the office.

"What was that! Dumbledore I demand answers! WHAT WAS THAT!" Screamed Umbridge hysterically as the elderly headmaster emerged holding an odachi in an obsidian sheathe with an accompanying chokuto, tanto and a kabutowari.

"Harry, I have no time to explain but you need to have faith in me. Under no circumstances must you ever draw this obsidian black sword...It will reveal a side of you that your mother, father and one of your half-brothers sealed away when you were born. The other weapons are free for you to be used. Also I need you to get away from Hogwarts one of the salt foundations has been destroyed in the North Eastern section of the castle that's why the demons are getting in...Yes demons Harry. You can see them because of your blood and I can see them as I trained as an exorcist...I'm not making sense as I need to help the school." Ordered Dumbledore as he handed Harry a sleek black device.

"That is a mobile phone. Again one of your half brothers made it for you, it's got a number programmed in. When you get clear you are too call that number. The person was your mother's magical guardian."

Harry turned to the demon in the office and unsheathed the Kabutowari "I don't know who you belong to but you're going back to hell!" Harry declared and with one fell swoop cleaved the head off the ghoul.

Dumbledore smirked _"Mephisto he really is your brother. The blood of his fathers run thick within him. I hope his mortal father's blood can restrain the blood of his other father."_

The headmaster lead the way down the stairs "Into the light I command thee! Cast away the mortal veil and reveal the demons!" Shouted Dumbledore in perfect hebrew as he flung open the doors to the Great Hall. Harry wasn't sure how he knew hebrew but right now he wasn't questioning it as demons were attacking.

At the Gryffindor table the moment the demons were revealed Seamus grinned as did several of the other Irish students. Ireland was located next to a Gehennna Rift of Rot, they had memorised the latin and gaelic verses for booting Rot demons back to Gehenna.

"In the name of Cuchulainn, we send you back with greetings from the Emerald Isles!" Screamed Seamus and several dozen other students launched their own prayers annihilating the Coal Tars with massive bangs of thunder and cracks of lightning.

Harry rallied the school and they slowly but surely began throwing back the minor demons. Harry split the skull of another Ghoul when his unoccupied left hand spontaneously erupted into purple flames "GO BACK TO HELL!"

Seamus's eyes widened he had recognised those flames they were flames from the 'Blue Night' said night had claimed his three older brothers and six entire branches of his mothers family. His mother was the youngest of eight children and Blue Night claimed six of them and their families.

" _Harry doesn't need anymore shit...I've given him enough."_ Seamus thought as the last of the demons were destroyed.

Harry was panting and he eyed his birth marks on his left hand they were now pitch black! "DOBBY!" Harry snapped and the house elf popped into existance.

"How can Dobby serve Master Harry Potter?" Squeaked the elf.

"I need my..." Harry didn't finish his sentence as his luggage emerged with bang.

"Where do you think you're going?" Asked Madame Umbridge in her too sickly sweet tone and Harry decided to be a bit of an ass.

"Away from you. Away from your face. Away from your voice. Away from your personality. Oh and away from your damn ugly family." Snapped Harry his temper threatening to get the best of him.

"And if I refuse to let you go?"

Harry unsheathed his chokuto and held it to her neck "I take your life. You owe me a life debt and taking it would settle it just good for me." Harry rumbled flames dancing in his eyes.

Before Umbridge could say a thing Harry had left the castle. The moment Harry cleared Hogsmeade he pulled out the phone and dialled the number "Johann Faust speaking..." A Japanese accented man said on the phone.

"My name is Harry Potter, my mother was Lily Evans..."

Harry felt something on his back and he turned around and his eyes widened the stranger was garbed in an interesting array of colours of a white suit with a top hat that had a purple and pink ribbin around it; pink spotty neckerchief; white umbrella and purple point shoes "Hello Harry Potter or should I say little brother, I am Johann Faust or Mephisto Pheles..." The man said with an elegant bow.


	2. Chapter 2

Aka no Ex  
Red Exorcist  
Blue Exorcist/Harry Potter crossover

 **Darksider82  
Anyone**

 **Zwei: Mephisto Pheles/Samael/Johann Faust V**

Harry stared at his supposed 'Magical Guardian' "Okay...Why are you here? How am I your little brother? Can someone be BLOODY STRAIGHT WITH ME!" He finished flames erupting around his hands.

Mephisto sighed and with a murmured 'Ein, Zwei, Drei' opened his umbrella dousing the enraged teen in freezing water. Mephisto chuckled, oh this little brother was so 'KAWAII' when he was angry. "Okay Harry-chan, I'll be straight with you but first I need you to grab my hand. Ein, Zwei, Drei!"

Time suddenly stopped almost as if someone had pressed pause on a remote "Okay, Harry, my name is Mephisto Pheles, you probably already new that. I'm head of the Tokyo branch of Exorcists, I'm also known as Johann Faust and I'm the principle of True Cross Academy...I know what you're thinking 'What does this have to do with anything.' The answer is everything, I need to finish explaining myself first...Where was I?"

"True Cross Academy." Supplied the Half Demon.

Mephisto nodded "What even fewer people know is that my true name is Samael..." He trailed off as Harry's eyes widened, he had read about Samael.

"Samael, 2nd of the Demon Kings and King of Space and Time. Second of Satan's three or four children. The others being King of Light, King of Earth comfirmed and supposedly either the Kings of either Fire or Rot."

Mephisto chuckled "Satan just had three of us. Amaimon, Me, Lucifer baby to eldest...Yes I know I'm an exorcist; I don't particularly like tou-sans idea of world domination. Okay Harry what do you know about Gehenna and Assiah?"

Harry's mind was flicking over all of the books he had read "Gehenna is the realm of demons and Assiah is this world. Demons the lower to some of the higher tiers can be summoned in whereas those of the rank of King have to possess things."

Mephisto nodded "Correct on all accounts. Now Satan, he can only possess certain people. No-one in Gehenna has been able to work out why...I digress...He possessed a baby who wouldn't live for more than three days and succeeded but lost access to most of his powers but hey, he didn't listen despite me warning him. The baby was James Harold Potter, when we get to Tokyo we'll do the diagnostics and if I'm wrong I apologise."

Harry nodded "Just alot to take in. I'm supposedly a Son of the Devil, one of my Half-Siblings is an Exorcist and the other two?"

"Amaimon's a drifter that causes mayhem for mayhem's sake. I cause it for a bit of fun providing minimum casualities and Lucifier well he's a bit of an arrogant twat. But anyway let's go. I can tell you more about my dear step-mother/ward..." Mephisto let out a sigh "...The family is complicated..."

Harry snorted "Things are looking better brother...Now let's go."

Mephisto grinned and time resumed "Ah the car's here."

Harry found himself amazed and horrendously confused, he was half demon; his uncle was a Demon King and a brother and he had three of them as far he knew and now he was going to become an exorcist.

Mephisto spent the five hours in the car talking to Harry about the boys mother and the elder mans step-mother and what she specialised in at Cram School "Uncle, I want to become an exorcist. I want to prove that anyone can change."

Mephisto grinned "What's your meister going to be? Your speciality? We have Knights- Sword Exorcists, Dragoons- Ranged Specialists, Aria's- Bible Exorcists, yes much like the Exorcist film. Tamers- Summon Demons to fight others and Doctors- Healer Exorcists. Your mother was a Dragoon and Tamer."

Harry grinned "Dragoon, Tamer and Knight. I'll always have a way out."

It took twelve hours but to Harry it felt less as he finally had what he always wanted, information about his mother and father. Yes he was slightly unnerved that his father was devil but hey, he had some information.

"Uncle, could you teach me japanese and how to control these?" At that Harry ignited his hand, the flames erupted as a birght azure blue but rapidly turned purple.

Mephisto stared "Mother was a crafty one...She must have performed a runic sequence to bind the blue flames or at least mask them so it looks like you have a different demonic father."

Harry grinned at that and soon enough they touched down in Japan. He didn't remember getting on a plane at all; he remembered entering the car and that was that "Space and Time King, little brother."

Mephisto bounded out of the car, Harry having to jog to keep up with his elder brother. The pair entered a doorway and ended up in a bustling high street and hight above the stood even more impressive buildings "Welcome to Peninsula True Cross, True Cross Academy is up the top and everything supplies our needs...We have much to do and so little time."

Harry rolled his eyes "You CONTROL Time big brother."

"It's aniki or nii-san, ototuo. Your first bit of Japanese, the first two are the formal and informal ways of saying big or elder brother. The last word means little brother."

Harry nodded as he processed the mini-lesson, he had already noticed small changes; his eyes were sharper, teeth and ears were as well plus he found recalling information just the slightest bit easier.

Within fifteen minutes or rather three hours because of Mephisto altering time, Harry was now registered in True Cross with Mephisto posing as his guardian with the title of 2nd Cousin once removed and the trusty alibi of 'We weren't close but family is family.' Harry found himself in a corridor in front of a large door.

"Drei, Zwei, Ein!" Called Mephisto and he transformed into a small dog as Harry pushed the door open.

"Ah Potter-san, Pheles-Dono said you were going to be arriving...I'm your Aria or..."

"Text preacher Knight sensei. For those who have are more of a classroom based learner."

The teacher nodded "You're intending to Meister in?" She asked curiously, then she noticed the Chokuto on Harry's back "A Knight?"

Harry nodded and revealed a Sig Sauer "Dragoon and hopefully a Tamer as well."

The teacher nodded "Come in grab a seat we're going over the texts required to exorcise Rot demons."

Harry nodded "Greetings from the Emerald Isles! In Gaelic is the only incantation I know...Last school as it was overrun had several Irish blooded students. Britain has the highest concentration of Rot demons anywhere as its located next to a Rift of Rot."


	3. Chapter 3

Aka no Ex  
Red Exorcist  
Blue Exorcist/Harry Potter crossover

 **Darksider82  
Anyone**

 **Drei: Meeting the Peers**

Harry detested being looked at. It made him feel like animal. Considering the part of him sealed away restricting his animalistic part was a demon and his status as a demon it was fitting. Samael had shown him a baby photo of him covered in flames with his clawed fingers, wings and tail and in Harry's own opinion he looked cute in a demonic sort of way.

In a disturbing way Harry was tempted to unsheathe the slaying sword Totsuka-no-Tsurugior more affectionately known as 'Sword of Susano'o' to return his demonic side and let fly his wings once again. But decided against it unless it was seriously needed.

"Hari-san can I ask why you have so many blades? My name is Izumo Kamiki; I hail from a long line of Priestesses in the worship of the Goddess Inari." A girl announced. _"KILL THE DAMN MALFOY BITCH!"_ His inner voice screamed.

Harry nodded "It's a pleasure to meet you Miss Kamiki. As for so many blades my blade of choice is tied to my life force...So the ramifications of drawing that one...I need back ups basically." He wanted to get rid of her as quickly as possible.

"You mentioned worshipping Inari? What are the perks?"

"You really don't a know a thing..."

Harry's temper spiked and smoke began to emerge from his finger tips "NEVER patronise me...My family come from a long line of elementalalists my dad had exceptional potential in fire and as for me care to guess."

Izumo quickly back away as Harry placed his hands in a seal known which was unknowingly the tiger seal and soon enough the smoke faded away.

Harry was introduced to Konekomaru Miwa, Renzo Shima and Ryuji Suguro; the trio were Aria's and Tamers in training though Renzo was training as a Knight as well because of his family traditions and Ryuji had expressed an interest being a dragoon.

Harry smirked when he nodded to Nemu and Yamada. Those two specifically the latter screamed 'Not student', he was going to have fun working with those two.

"Harry-san may I have a word?" It was Nemu, Harry looked twice before realising that it was the puppet on his arm that was addressing him.

"Sure, who do I speak to? The puppet or the body?"

Nemu's eyes opened "Me...I know Kuri-kun, I'll go back to sleep afterwards. I see you've noticed the fact that I'm not an ordinary Exwire and neither is Yamada. We are here on behalf of Mephisto Pheles-sama to keep an eye on you and the Okumura brothers...I understand you have four swords and one of them keeps your other half at bay."

Harry wordlessly handed Totsuka over to the exwire "I'm an official exorcist of Upper First Class in skill but due to me being only 14 I still need to attend this stupid cram school."

Harry snickered "I feel your pain. Mephisto's probably already told you about my being a wizard."

Yamada flipped his hood back revealing himself as a very attractive female "Eyes front gaki."

Harry's eyes widened "Okay my days seem to be more bi-polar than I am these days. I meet my snobbish peers because everyone seems to 'wrap me up in cotton fucking wool' and now I've met a drop dead gorgeous woman who could easily stop my heart as well as restart it."

Yamada smirked "Names Shura, Upper First Rank and your Knight instructor once everything's in place."

Harry suddenly hit the ground smoke gushing out from underneath his long sleeved shirt of the True Cross Uniform "Sleeves...Roll...Up." He growled as he fumbled with the buttons his hands begin to blister and blacken from the intensity of the smoke.

Shura pulled a knife and cut away the sleeves and her eyes widened when she saw the charred black outlines of claws etched into the teens skin "Not tattoo's birthmarks. More serious my life is in danger either from self or someone else they burn."

(As Harry's arms blackened)

Rin snarled as he tried to jump onto a small monkey demon. It dodged out the way and sent him clattering into the pyramid of tinned goods that had been stacked precariously high in the middle of the supermarket.

Needless to say for the elder Okumura the day was going to get a lot worse; and unknowingly for his younger brother much more difficult and painful for his half siblings.

(Back with Harry)

The elder exorcists watched as the marks blackened and smoke began to emerge again "We're going to need..."

Just then a white dog appeared and in its place was the Honory Knight Mephisto "My dear cousin what's gone wrong now?"

Harry managed to sit up "Tall, black hair, supermarket, monkey demon, church, gate in floor, blue flames." With that Harry's eyes rolled into the back of his head.

Shura put her head in the door and noticed the petrified exwire students thinking quickly "Newcomer can divine people through flames...Sometimes the visions are worse than others."

"Flame divination? Really Shura? The best you can come up with." Said the puppet.

Mephisto giggled childishly "Oh it appears another pawn for Satan has appeared...Oh Shiro how are you going to deal with this."

Harry groaned and as he opened his eyes he found himself looking at his half brother "Not the sight I want to be looking at Nii-san." Mephisto smirked and Shura entered his vision by crouching down and tilted his head towards her.

"Much better sight."

"Little pervert aren't you."

"Can't help but admire what the eye can see. And you Shura-chan are beautiful what you doing after tonight?"

Mephisto, Nemu and the Puppet were fighting the smirks and the laughs, this guy was absolutely insane "I'm 22 gaki you're what 13?"

"15 actually shitty upbringing but I'm working on that."

"Wait until your 17 and ask me again if I don't have a boyfriend. I like you but I don't know you well enough yet."

"But you'd love to...Okay all the jokes aside help me up now I need to do bullshitting-101."

"What did you see?" Asked Ryuji almost immediately.

"A pain in the ass, blue flames and a church. All I know is it hurt like a proctology done with a fist instead of a finger."

Konekomaru winced "That screams painful..." Then he noticed the marks. "...Nice tattoo's."

"They're not tattoo's they're part of a birthmark..."

Renzo stared "I'll believe that when I see it."

Harry groaned not even been a day and he was already pulling his clothes off, he smirked this'll be fun. He pulled the tie off and peeled off the shirt and to everyone's surprise the claws were on his fingers and they traced the marks up to his the newcomer's back where wings sprouted off his spine. "There more to it? What does it look like?"

"Right down the backs of my legs and they look like tails or one bloody big tail...I don't particularly wish to do the full monty not without being paid."

"Is that all you think about? Money, women and what the hell happened to you!" Exclaimed Izumo.

"Money gets stuff done. I'm a young man with a healthyish mind and a good amount of respect for the female figure and I will say as much if I think it. Oh and stabbed, drowned, broken ribs, poisoned..."

"You should be dead judging by the amount of scars you've got."

"Yeah, I get that a lot. Oh and anyway thankgod this has happened during break as we now have taming."

The tamer was a tall of man of Russian origin, He gave a nod and a standard 'welcome to taming' and began explaining the art. He handed out sheets of paper with a pentagram drawn onto them "Drop three drops of blood on the paper if it glows at all then you have potential to become a tamer."

Harry pulled out his Chokuto and wrapped his hand around it and yanked down the blade allowing his blood to flow freely. It touched the paper and it began to glow a bright red. Izuno and Rezo were the only other ones at the moment to have the potential to summon.

"Now grab the paper and use whatever words that come to mind."

Izumo went first "I humbly call upon the Goddess of the Harvest. Follow my wishes, leave none unfulfilled!" The power swirled around her and her taking the form of two foxes.

"I call upon my accursed blood grant me my champion!" Called Harry if powered swirled around Izumo, Harry was standing in a virtual storm, the winds howled through the room messing up his already messy hair as four Djinn appeared. One took the form of a Gargoyle, Another took the form of a Three eyed two headed crow, One looke like a warrior of Anubis and the forth was the form of a cat.

Everyone stared at him "What these punks looking at?" The Gargoyle demanded his luminescent eyes glowing madly.

"Hush Bartimaeus. Shall I detonate them?" Asked Anubis lookalike.

"Jabor! First time since the Fall of Prague we've been summoned and you want to kill these people, I hate you." Called the cat.

"Shut up Mwamba not like you've brought anything to this world." Replied Jabor sullenly.

"Alright assholes break it up. Names Farquarl boss yes I like this two headed crow look because quite frankly you can't contain so much badass in a single headed crow. Cat's Mwamba a shapeshifter. Jabor is the Dog haired thing he's a masters best friend only not as bright and the Gargolye is Bartimaeus. How can we serve?"

"First of all you can all shut your traps. I just used raw power to see what I could summon."

"Well if that's all then we'll be on our way."

(A/N)

I will be using the demons from Blue Exorcist but I decided with Harry being a Tamer he should have some smart ass and powerful minions. All four of whom are from the Bartimaeus Series. 


	4. Chapter 4

Aka no Ex  
Red Exorcist  
Blue Exorcist/Harry Potter crossover

 **Darksider82  
Anyone**

 _Quick explanation of the family tree_

 _Lucifer's Demon Sons:  
Amaimon  
Samael/Mephisto Phelese/Johann Faust V  
Lucifer_

 _Half Blooded Sons (w. Yuri Egin)  
Rin  
Yukio_

 _As James Potter w. Lily Evans  
Harry_

 _Now we all know that James (Satan) married Lily and had Harry thus making Harry a Prince of Gehenna and his mother becoming Satan's true demonic sons step mother. Nothing else has changed Harry is still the half brother of the Okumura twins and half/step brother to Amaimon et al._

 **Vier: Hello Ototuo**

Everyone looked at Harry surprised even Igor Neuhaus who was one of the more powerful Tamer's in the order "Do you know what you just summoned?"

Harry shrugged "Not to be rude sensei I've only just started so no...All I'm guessing what I summoned and how many I summoned should not have been possible."

Igor nodded "You summoned a class of demon known as Djinn which aren't in any of the known kin."

"You mean the Demon Kings and their kin or minions? Yeah I kinda get that a lot. What does that mean?"

"Djinn are a mid-rank demon in the table of demons from our Summoner allies in London..."

Harry's eyes flickered red "I call upon the blood in my veins bring my champion! Bartimaeus your master summons you." Harry snarled slamming his hand down on the wood and the gargoyle appeared.

"You called master...What can I do to help?"

"The London Summoners, do they exist?" The gargoyle chuckled ominously.

"Yes and no; you see sir the summoners had a little bit of a scrap and things got heated to the point where daemons were merging with their masters to utilise powerful weapons of even more powerful magicians and all in all the bastards killed themselves off. I should know, I was their it was wonderful...I took a chunk out of Big Ben; chucked an oldfriend into a Rosemary box and chucked him into the Thames. Blew up a few old tombs in Westminster...All in all it was a ball. Some of them survived and most died so basically sir yes you can learn more about us and could have joined us Harry Potter but your training would have been self taught."

Harry's flickered red "I never told you my name..."

Bartimaeus smirked "I make it my buisness to know things Harry...I'd really recommend you change it. Harry seems to much of boys name you've got a bloody destiny ahead boss and you're going to have to lead your friends and fellow exorcists against old Tom Riddle."

Harry paled, Igor quickly moved in to banish the Djinni "I'm sorry Harry...I'll be waiting your call."

"What was that about?" Barked Ryuji his hand going for one of Harry's swords.

"None of your buisness...You touch any of my swords..." Harry drew, turned the safety off his hand gun and pointed it at Ryuji "I'll blow your bloody brains out."

Just then the door slammed open and two bullets slammed into two carefully positioned targets next to buckets of water. Harry jumped backwards backflipping in the progress leaving Ryuji to get soaked in water.

"All right you lot settle down..."

Then the door opened and a tall kid walked in "YUKIO!" The boy shouted, Harry immediately realised something this was the guy from his vision.

"Not now Rin...Sit down." Ordered Yukio.

Harry grabbed Rin by his sword bag and pulled him down and made sure to grab the tail as well. Rin fought back a yell and he sat back down in his seat next to the guy who evidently knew what he was "What was the big fucking deal?"

"Stop you blowing your cover and revealing what you are, plus I'm interested in what he has to say. I'm Harry by the way Harry Potter."

Rin nodded as Yukio began the lecture on the role of a dragoon, Rin quickly found himself falling asleep "Ack." Harry had jabbed him in the kidney.

"I can't believe Uncle allowed you in if you're going to fall asleep in class how the hell are you going to achieve what you're going to achieve."

Ryuji snorted "What about you then? You run away from home because your mother..."

Smoke erupted from Harry's clothers and it began to form into wings "Never insult my mother you insignificant piece of shit." Harry crowled as the birthmarks surged around his fingers rapidly morphing into smoke like claws.

"Bon that's enough. He's a good guy...Come on Bon." Pleaded Konekomaru trying to pull Bon back into his seat.

"You want to fight?"

Harry grinned "Lets go then."

A gunshot rang out bringing the class back to order "I will not have Exwire's beating each other to Gehenna because of one peers interaction with another. Harry quell those flames." Snapped Yukio before regaining control of the class.

They had Yukio twice that day for four hours; two for Dragoon classes and two for Doctor classes. Harry was positively twitching _"Fucking tumeric...Who knew...Oh wait Snape and Pompfrey."_

The class was dismissed leaving Harry, Rin and Yukio in the room. Harry tuned out as Yukio began to state 'He knew about demons' and Rin's secret 'Son of Satan'.

"Rin, Yukio shut up the pair of you."

Harry found himself staring down the barrels of the youngest Exorcist Dragoon Doctor and he chuckled "Yukio you're a bit of a hypocrite. You're both sons of satan, you're the lucky one Yukio because you haven't activated your blood. I want to tell you two that the pair of you aren't alone little brothers."

Rin's eyes widened "Why don't you have your powers out?"

"I have someone out for my life because of another set of skills..."

"...You mean magic don't you cousin." A deep voice said from behind them.

"Cousin...Or is it Headmaster?" Harry replied nonchalantly to the Honory Knight.

"As of right now considering your welfare its Cousin."

"Is our cousing?" Blurted out Rin getting a booming laugh from Mephisto.

"No, Oh young Okumura I'm Harry's second cousin on his mothers side...Please keep it to yourselves about Harry being a wizard...Don't worry the Japanese Ministry know you are here and since you haven't yet signed documents saying you want to stay here they can't do much to help you."

"I like it here so far my peers...not so much. Would have had my cover blown because of that priest brat."

"Priest brat?" Questioned the elder Okumura brother.

"Ryuji-san am I right Harry? When we're alone I don't mind facing my cursed blood you said you're our brother when were you born? We were December 27th '81."

"July 31st '80."

"Okay nii-san...It means big brother." Explained Yukio to Harry who looked confused.

"Mephisto told me one it began with 'Ot' something like 'Oto' or 'Otter'."

Rin snorted "You mean Ototuo. Means little brother."

"Yeah thats it...Yukio can you help with Japanese."

Yukio grinned when suddenly Rin sneezed and slammed into the desk knocking a phial of blood off the table "Accio." Harry whispered and the phial jumped into his hand.

"What's this for?"

"Sight of hazing ritual...Allows those without unique blood to see demons. Also summons Hobgoblins as the first exorcism." Explained the young professor.

Harry smirked demonically "I'll set up the ritual and you get the rest in Ototuo-sensei..."

"What about me!" Called the elder brother, Harry merely flicked his wand and the chords wrapped around Rin's hands, feet, legs and tail getting a yowl of pain.

"Sit their and try not to blow us all to Genhenna."


	5. Chapter 5

Aka no Ex  
Red Exorcist  
Blue Exorcist/Harry Potter crossover

 **Darksider82  
Anyone**

 **Funf: Hazing Disasters and Interesting Altercations**

The ritual was set up to allow those who had no demonic blood in their veins accustomed to it so they could see the foe. Yamada, Harry, Yukio and Rin along with a disguised Mephisto observed as the students were hazed.

The results were interesting to say the least. Bon and his two comrades who came on his scholarship staggered around noisily and clumsily as if they had been drinking heavily. Izumo and her friend clutched their heads harshly as a massive headache rushed over them whereas Shiemi just gained a large absent minded grin. The hazing didn't effect her as much as the others because of a possession from several plant demons.

Harry kicked Rin several times beneath point where his tail protruded from getting the kid to wince. "Keep it in your trousers or wrapped around your waist idiot."

"Don't tell me what to do." Growled Rin.

"I'll tell you what to do if it means I keep my head attached to my shoulders." Harry grumbled already itching to unleash his demonic form and smack his impulsive younger brother around.

The lesson ended shortly after the ritual to prevent the students from getting injured in their next lesson which was in running away from a tamed demon.

It was set in the style of a race you had to keep away from the demon for three circuits of the arena.

At the current moment Harry was hauling ass around the arena with Bon in tow. Bon snarled as this no-body with no background of exorcist training was beating him in a footrace! HE was the one who was going to beat Satan and no-one else. He didn't need them, all he needed were his two friends and that was it.

Plus he didn't like Okumura or the new guy anyways mainly because one had been sponsored by the headmaster and the other was also sponsored and had a brother in the ranks as well.

Harry made it around the circuit easily avoiding the demon in question before it was yanked back into its cage "Winner Potter Harry. Exceptional footwork on the fly but more planning is needed but that will come in time."

The pair climbed out as Rin jumped into the arena with an underly enthusiastic Renzo. The demon was released and the pair began to run "Idiots the pair of them."

Harry didn't need to look up to see Bon standing behind him "What can I do for the one with the scholarship?"

"Answers...now." Demanded Bon his hand reaching for the sword that concealed Harry's demonic half. He found himself staring into the barrel of the Sig Sauer from earlier on but this time the safety was off and the hammer was cocked back.

Within moments their Physical Exertions tutor was amongst them grabbing the Sig Sauer out of Harry's hand whilst turning Bon away taking care not to grab the cursed Odachi on Harry's waist.

"What is going on here?" He thundered causing the demons to lose control and rush towards the two boys.

"IZUMO! THROW THEM THE CHOKUTO AND TANTO!" Shouted Harry sending the swords towards the purplette with the heel of his shoe.

Izumo nodded but the demons were already back in their cages with Yukio observing them "That's enough...I'll deal with my brother and Harry."

Bon smirked at the two Harry's eyes flashed blue and deep purple flames that were slowly becoming red erupted from his hands "Come on Bon...Think you can take me in a fight? How do you want it? Fists? Weapons? First blood? Death?"

"Ein, Zwei, Drei! Cease this at once." A softly spoken voice stated and time came to a halt and Harry saw Mephisto standing in front of him.

"Harry-chan I rarely interact so I'll make this quick calm down." With that Mephisto vanished.

Harry concentrated and the flames retracted causing the Demons to look at him and Rin with something akin to loyalty and fear.

"What are you?" Asked Bon repeatedly getting annoyed at the no-body.

"We finished sensei?" Harry asked the teachers getting nods of confirmation with that he got his swords back and his hand gun and left the room.

Bon was the second to leave and this time he placed his hand firmly on Harry's shoulder. Harry reacted quickly, his left hand grabbed Bon's right hand wrist, twisted it sharply contorting the arm until it the traction was made. With his other hand he grabbed Bon's upper arm and in one relatively smooth movement drove his elbow into the humerus followed by strikes to the radius and ulnar (All three bones in arm above the wrist.) Bon collapsed to his knees grasping his arm.

"Next time it'll be worse." Harry growled before stalking off and almost ploughing into Yukio.

"Gomenesai sensei." Harry murmured as he turned to avoid the young dragoon.

"Your japanese is improving...You're heading to the dormitory's. You're staying with Rin and me. Officially its to help me control my brother and unofficially..."

"No more be said little brother. Rin'll learn eventually because I will make him." Growled Harry flames flickering in his eyes.

Meanwhile in his office Mephisto's eyes widened because of a wizards natural ability to see demons they were able to void them. Which made the demon snarl. 'Wizards whenever something doesn't seem good bury your head in the sand and hope it goes away...How pathetic.' Mephisto thought savagely.

Things were worse than ever. The last time exorcists were needed to intervene was in World War Two when Grindlewald had managed to swing four of the demon kings to his aide; yes they were lower ranking Demon Kings but still a Demon King is a Demon King.

 _Mephisto,  
How's Harry settling in? It's getting pretty rough at my school. I've just had to repel several waves of demons. Nothing to be concerned about normally but with the sheer numbers of them I'm writing for assistance._

 _I've sent for aide to the British Exorcists, the Vatican and now you. I believe its because Voldemort has performed some extremely dangerous magics that have caught the demon kings eyes._

 _Hope to hear from you accordingly  
Albus Percival Wulfric Brian Dumbledore; Order of Merlin First Class, Headmaster at Hogwarts School of Witchcraft and Wizidrary, Honorary Knight of the British Branch of the Order of Exorcists._

Mephisto grinned he knew Dumbledore from a long time ago. He was the one that got Dumbledore into the Order and even he was shocked as the man became an Upper Second Class Exorcist within five years which wasn't unheard of but was definitely rare. He could have gone on to serve as Arc-Knight or even Paladin but decided to halt his advancement at an Honorary Knight to turn his attention to teaching.

It was even rumoured that Arthur A. Angel the current Paladin and former pupil of Dumbledore's asked the elderly man for advice.

He pressed a button on his office phone "Send for Exwire Potter Harry his timetable has changed."

That afternoon Harry was in the shower when four Second Class Exorcists knocked on the door "Harry get the door." Shouted Rin.

"I'm in the shower asshole. You get the door."

Yukio shook his head "I've got it."

"Thanks Yukio." He heard from the shower.

Suddenly the Second Class Exorcists burst into the apartment "Can I help you?"

"We're looking for Potter Harry, Sir Pheles wishes to speak with him where is he?"

Yukio pointed to the bathroom and one of the Exorcists a female booted the door open and entered "SWEET JESUS!"

"GET OUT! ASSIAH ABOVE! IF SOMEONE INDICATES THE BATHROOM ONE DOES NOT JUST BOOT THE DAMN DOOR OPEN. WHO ARE YOU LOVE? Ah Second Rank Exorcists okay then the 'snap and rub' icepacks are in the cabinet to the left of the one above the sink okay please close the door on the way out and tell your colleagues I'll be with them the moment I'm dressed."

"Find him?"

"Yes...In the shower. Cute though."

"You're meant to be professional Hyuga."

"Kind of hard not to when you disturb his shower and he swings round revealing his..." The other female exorcist swiftly covered Hyuga's mouth.

Harry joined them obsidian sword on his waist "We off then gentlemen? Women? Perverts?"

ab


	6. Chapter 6

Aka no Ex  
Red Exorcist  
Blue Exorcist/Harry Potter crossover

 **Darksider82  
Anyone**

 **Sechs: Oh boy, buckle up, this is going to suck**

The ex-wires all piled into Mephisto's private jet along with various other exorcists of different tiers and specialisations. Harry groaned as he gripped the blade that contained his demonic powers like a life-line, his hands turning white and the marks turning black.

"This is going to be easy." Called Bon calmly getting a snort Harry. The dark haired teen really didn't like the prodigy's attitude, Harry would by hook or crook make Bon's life miserable when they finally landed in England.

"No it really isn't." Harry growled before fixing everyone with a hard glare making them think twice before commenting even Rin had the sense to remain quiet considering how the guy was his brother but he wasn't sure how.

Yugao Hyuuga an exceptionally talented seventeen year old second class Exorcist and the one who had booted the showerdoor down and still got red whenever she and Harry were in the same room.

"Harry just what are we facing back in Britain?"

"Assholes, Rot, Assholes of Rot and potentially Rotting Assholes oh and my temper if someone screws up...Whose directing the field trip?" Harry growled.

"I am." Harry didn't even need to look to know that Mephisto was with them and he would be leading.

"What's the mission uncle?"

"A little pest control, nothing more and nothing less."

"This pest control wouldn't have anything to do with me being an orphan?"

Mephisto stopped and too quickly for anyone to see aside from Rin and Yukio to see. With that Harry closed his eyes and fell asleep, or rather into a mediatative trance as he allowed the memories of his language lessons with Mephisto to wash over him.

The brothers were as close as they could be without giving something away and Harry to release his powers which would be amazing but also very dangerous.

The plane touched down in Heathrow and Mephisto took charge dividing everyone into groups with the exception of his group consisting of Harry, Rin, Yukio, Yugao and two other knights both of whom were Upper First's and witches who had combined their wands with their swords.

"I call upon my cursed blood...Farquarl HEARKEN TO ME!" Farquarl erupted into existence.

"Can I help?"

Harry nodded "British Magician Headquarters? Is it intact or ruins? Are their safehouses and vaults that are available and will I need assistance to enter them?"

Farquarl groaned at his new summoner "You really don't ask for much. The Mona Lisa would be easier or even Birth Of Venus."

Harry flicked his hand open and a fireball appeared making Farquarl step backwards, the last time he had seen a detonation was just before Bartimaeus and his master had ripped him apart with that infernal staff of Gladstone's "Yeah, I know where it is."

"Lead on." Harry commented grabbing Sig Sauer with his fire encased hand when the gun became more skeletal.

Yugao stared at the transformation "That's..."

"Interesting Yugao? Yeah curtesy of a curse on one side of the family and never manifested like this until now."

Yugao could only nod "Makes sense...What's the catch?"

"My full power is trapped within a sword and if I draw it well bad shit." Harry replied as he jumped over a skip adnd helped her down.

"How bad shit is bad shit?"

"Bad enough that people will want him for experiments..." Farquarl stated from a doorway "...In here."

The two First Class Exorcists opened the door and their jaws dropped "Sir, we've got to..."

"...Do nothing." Harry growled unsheathing his Chokuto moving his Obsidian Odachi across his back diagonally.

"Why?"

Harry pointed his gun at the Tamer "My mothers side of the family were the survivors of the British Sect of Magicians where you are standing co-incidentally is my property. So you will not touch a damn thing unless I say so."

The Dragoon squared himself up against the teen and he reached for his knife and Yugao drew her sword "Whatever you're reach for had better be something edlibe, because you're gonna have to eat it."

"Yeah it will be! GLORY TO LORD..." BOOM! Harry squeezed the Sig Sauer trigger and the dragoon dropped to the floor.

"You had best recieve the highest honour's from your Lord because I'll turn him and his friends skulls into canoes." Harry growled as he peeled back the mans shirt to reveal with Dark Mark.

"Son of a Bitch!" Harry spun on his party "Reveal your arms and remove any covering."

Thankfully the rest of the group were clean "Farquarl get rid of the body and you're free to go."

"Can I eat it?"

"If that's how you prefer to dispose of things..." Farquarl didn't listen to the rest as he shifted into a serpent grabbed the body and vanished in a plume of smoke.

"Pretty grim summon." Yugao said, Harry smiled wolfishly.

"He's not even top tier for his class of demons. I can summon much worse. Anyway bag everything but be bloody careful with those spheres."

The entire warehouse was emptied and placed into five extremely deep bags woven with Mephisto's time space abilities "Where to now?" Harry asked curiously.

"The Cauldron and then we go to the School." Replied Mephisto getting groans from the wizards.

"God I'm hating this assignment already." Harry grumbled in Japanese as he dodged three cars who had overshot red lights and pulled Yugao back as the cars honked at them.

Harry flicked them the bird "Let's go…Welcome to Britain, drivers are dicks and the politics is worse."

Yugao grinned and the small detachment of exorcists rendezvoused with their comrades outside a broken down, dingy looking building "What we doing here?" Called Bon as he spied a place that looked far more comfortable down the street.

"Bon shut it. Now follow me. Rin, touch anything I'll beat you black and blue." Harry growled as he grabbed Yugao by the arm and he pushed open the door.

"Let's go follow the Ex-wire." Called Mephisto sounding like a kid on a sugar high.

Tom, owner and barman of the Leaky Cauldron was having a bad day. Ever since Harry Potter had proclaimed the return of Lord Voldemort his business had plummeted and with frequent demon invasions made things worse.

The British wizarding world were doing nothing to combat the demons and the British Exorcists weren't helping because they were too busy keeping the bigger and nastier demons from coming through and there was the fact that they had barely adequately trained exorcists.

Then the door opened and more exorcists entered, leading them "Harry Potter! Nice to see you once again."

Harry grinned thinly at the man "Same to you Tom…Mind opening up the Alleyway…We're here to deal with several pests."

"Potter…" Growled Bon.

"Bon, shut up…Now everyone let's go. Tamer's get your summons, Dragoons get your weapons hot, Knights swords loose, Aria's and Medic's…Look busy."

"Intending to be offensive?"

"Nope just honest. Somehow suspect one of the honouree knights and Mephisto have made me the leader of this mission."

Rin prepped one of the swords Harry had given him. Harry had grabbed his Kurikara and concealed it on him. Rin had tried to confront Harry but the Green Eyed Son of Satan had Rin by the lapels "You're too hot headed. You draw the sword without thinking and because of that Yukio, Myself and You will be having appointments with Caliburn and our heads will be rolling...If you screw up."

Harry grabbed his cursed blade and made his way through the bar, the punters making way for him and whispering ferverently. "Mr. Potter have you come back to help us deal with this demon investation?"

"No. I've come back because YOU CANNOT be bothered to do something on your own...Why should I?"

"Aren't you being a bit harsh?" Asked Shiemi nervously getting a snort from Harry.

"Nope. Anyway the time is awaisting." Tom opened the barriers and everyones jaw dropped.


	7. Chapter 7

Aka no Ex  
Red Exorcist  
Blue Exorcist/Harry Potter crossover

 **Darksider82  
Anyone**

 **Sieben: All Spit in the Street**

Diagon Alley was a war-zone, kindred of Rot and Earth were running up and down the Alley. Some were snacking on down Witches and Wizards. Harry groaned, unholstered his pistol and shot a passing Delkap which squealed as it combusted into flames.

The feasting demons stopped and stared as the Ex-wires and Knights entered the Alley "All right...You demons have got five seconds to leave or be deported." Harry called unsheathing his chokuto and moving his obsidian blade into position should he need it.

"You are bluffing." Called a Naga who was about to devour a small child, two shots cracked out and the Naga fell dead in thirds.

"Five." Announced Harry "...Team up. Ex-wires stick to a senior knight and obey them. Yukio you have my permission to knock out Rin should he disobey you. Yugao, coffee should you not become too scared of what I truly am? And we survive this."

With that Harry unsheathed the chokuto and charged into the fray. He swung the blade in a smooth arc, splitting Earth and Rot demons in half "Potter! I thought you said only Rot demons!" Shouted Bon as he exorcised seven at once.

Harry snorted "I said possibly. I was right wasn't I?" He shouted, grabbed Yugao by the waist and swept the pair of them to an almost 45 degree bend as a pair of Naberiui sailed overhead. Yugao grinned and pulled the pair up, grabbed Harry's handgun and calmly put two rounds into the two Naberius's killing the pair of them.

"Tou-san taught me to shoot and hand to hand. I'm a Tamer primarily but I can handle myself." Yugao stopped, she felt a presence from behind her and suddenly Harry had rugby tackled her to the floor as a Demon roared and the sheer tone and pitch of the roar shattered the pavement and vaporised four stray wizards and numerous lesser demons.

Harry reached of Kurikara only to find a green haired man with a massive point on the dome to have taken it "Oh shit...Two of them! Harry we need to move now." Said Yugao getting up and grabbing the ex-wire's chokuto.

"JABOR! BARTIMAEUS HEARKEN TO ME!" Harry shouted as he fumbled in his rucksack and pulled out an aqua blue sphere and a yellow sphere, both these spheres represented an element wind and water to be precise.

The two Djinn appeared in a flurry of smoke "You called." Bartimaeus turned "Boss, I'm not sure if you realised but you're about to face off against Astorath and Amaimon."

Harry began recalling the types of demons but Yugao said it first "These two are Demon Kings of the demons attacking here and now. We need some first class Exorcists."

Meanwhile Rin had gotten himself separated from everybody and standing in front of him was Harry, the Exorcist who kicked down the door to the shower and four demons. He recognised two as Harry's summons but not the other two "Oh look Astorath! My half-brother is here." Giggled Amaimon childishly, Rin saw Harry jump up only for Amaimon to dropkick Harry with a sickening crack indicating at least four ribs were broken and Astorath had the black Odachi and Amaimon was carrying Rin's sword.

Harry sat up his Green eyes flickering with flame that seemed barely restrained, smoke was billowing off him and rapidly forming the outlines of wings and a tail "Yugao, I'm sorry…Get out of here." Harry ordered forcing the smoke off his fingers.

Yugao could only stare as Harry's skin seemed to emit smoke "Harry what's going on?"

"My curse. You know the bad shit, the more I emit smoke the closer I am for it to being released." Harry turned to face the Demon Kings, he pressed the two spheres in his hand and with reflexes akin to lightning flung them so hard, the duo hit the kings and exploded with the furiosity of a bomb, the water was whipped up into a vortex drenching the two demon kings parting their hands from the blades. But the damage was done for Rin as Kurikara was parted from Amaimon's hands the Green Haired Earth managed to loosen the seal on the sword and its sheathe.

Yugao's eyes widened as blue flames erupted around Rin and a tail burst through the ex-wires trousers "Harry want to tell me something?" She asked as she plucked the Odachi out the air and went to draw the blade.

Harry gulped and he felt an immense amount of demonic energy build up. "PALADIN ARTHUR A. ANGEL IS ON SCENE!" Called a tall blonde haired and white clad man wielding a massive sword and effortlessly bisected three demons at once.

The exorcist forces weren't taking casualties but the Aria's and Doctors were beginning to run low on supplies and how effective their voices were. The Dragoons were running low on ammo and the Knights were losing strength and the the Tamer's summons were beginning to be beaten back.

However, the Goblin defences at Gringotts were holding out as they repulsed demonic wave after wave that came charging up their steps. Arthur grunted as he was pushed backwards to Yugao and Harry the former of the duo still held Harry's bound powers. Harry concentrated his rage, grabbed his chokuto and purple flames jumped around the blade and he rushed forwards.

Arthur stared as Harry calmly sliced into Astorath causing him to roar with pain. Astorath went for a punch that should have cracked Harry's skull had the teen not tilted backwards and performed a standing backflip to avoid a jagged tail at knee height. Arthur's eyes widened as he saw the purple flames "He's Potter! Potter's are powerful elementalist's especially of the fire affinity and on occasion can conjure blue fire exactly the same as Satan's!" He turned to Yugao who was holding onto a black odachi and aiming with a Sig Sauer.

Rin was in agony, Yugao could see that. The cause of it was the King of Earth who was sheathing and unsheathing Kurikara surrounding him in flames "This is all my little brother has to offer?" Rin scrabbled to his feet and dived for his sword, but Amaimon skipped out the way causing him to crash into the building.

Harry snarled he needed more power, but he didn't need to risk his life. _"Embrace yourself, you'll win this fight and more to come."_ A deeper voice told him. He dodged two more attacks only to be flattened by Astorath's headbut. He went flying backwards and Bartimaeus jumped to his aid as Jabor unleashed four detonations ripping apart a building and several demons in the process.

"FARQUARL! MWAMBA! HEARKEN TO ME! The pair of you...help Jabor...Take them down...Bartimaeus, get me more elemental spheres." Harry growled as he sat up he knew his ribs had been cracked, looking around he saw Mephisto calmly assisting the downed exorcists and getting them back to their feet.

Yugao looked at the two Demon Kings and back at Harry then at the Odachi "Harry? Are you demon blooded?"

Harry grunted "Yesh. You pull that blade I'm dead." Arthur snorted "I doubt it, you need to defeat Voldemort...Yes I know of him, I'm a Wizard as well, I knew your parents." Harry grinned thinly and the flames appeared around his hands.

"Yugao, we definitely need coffee after this. Please draw the blade..." Growled Harry and hands shaking fearing what she was about to see, Yugao complied and everything changed.


	8. Chapter 8

Aka no Ex  
Red Exorcist  
Blue Exorcist/Harry Potter crossover

 **Darksider82  
Anyone**

 **Acht: Got an Alternative Solution?**

Harry's body convulsed as flames erupted over his, out from his tail bone erupted a massive tail which with what looked suspiciously like a scorpions stinger but with two points not one. Out of his back through his shirt erupted a set of skeletal bones which seemingly developed a sinewy membrane and along his arms his human skin began to be garbed in what could only be disguised as an exo-skeleton with darkened bones the tips of his fingers and toes to look like spikes. His headwas suddenly encased in a skull with purple flames erupting from its eyes sockets.

Then it screamed. Everyone stopped. Including Amaimon and Astorath. The surrounding minor demons immediately dissolved as the screams shockwaves hit them with the full force of a freight train. Harry grabbed a sword and it immediately took on a bony form with purple fire flickering along it. "Amaimon, Astorath...your fight is with me." With that he dissapeared and reappeared next to the weakest of the Demon Lords his sword lashing out and almost severing Astorath's head from his shoulders.

Arthur A. Angel stared and went for Caliburn but he stopped as he heard Lily's voice in his ears _'Cousin. Stay your hand. Harry has thoughs powers as a defence against the oncoming storm of the Death Eaters. Fear not him allying with the dark.'_ Angel stopped "Give him room." The British Exorcists dived out the way with Angel grabbing Yugao and the Obsidian blade as the Demonic Harry and Astorath collided with the pavement.

Astorath snarled and assumed his demonic form, an orb of pure rot in his hands "DIE! TRAITOR!" Harry smiled causing the skull to mutate grotesquely, the Rot Bolt shot towards him, cracking stone and shattering glass. Harry sliced the bolt into quarters causing them to disentegrate into thin air. "Traitor? I think not. You've come to this realm with intent to harm. I intend to send you back." Harry flickered forwards flames leaving the only indication of where he had been standing.

Rin, snarled in anger as Amaimon forgot to sheathe Kurikari and blurred forwards. His tail erupting for everyone to see and his ears lengthened and the blue fires of Satan erupting around him as he effectively rugby tackled Amaimon into the floor. His classmates stopped "Blue flames! Satan!" Gasped Bon as he rapidly tried to gain distance.

Shimei stared in wonder as her secret crush tackled the Green Haired King into the ground. She heard the snaps and cracks as people began apparating onto the scene, she smiled almost vindictively when one of them got incinerated by stepping between a battle crazed Harry and Astorath.

Harry was in the backseat of his mind as he let his demonic half sate his lust for battle. Astorath was positively terrefied of him, the King of Rot was in seriously bad health, he couldn't regenerate faster than the wounds he was gaining. His wings had been ripped beyond all recognition and in one case completely off, his tail had almost been severed causing him to shriek in pain "How are you so strong halfblooded bastard!"Harry snarled swung his sword, Astorath screamed in agony as one of his horns were cleaved off.

Mephisto chuckled serenely as he observed his half brother and half-step-brother put the two demon kings in their places "What will the pair of you do? The demon side will consume and burn everything you hold dear or will you become a human and die because you refuse to bond with your demonic half?"

Harry's demonic hearing managed to pick up his brother's murmurings "I'll kick this guys ass. BACK TO GEHENNA!" He snarled as he grabbed Astorath's flailing arm, twisted it and with one smooth motion sliced him in twain, finishing in a smooth circle sheathing the blade which was on his hilt and he forgot why he had it. Yugao quickly found the sheathe and holstered the demonic blade.

It was like a circuit being switched off. One moment Harry was going all demonic Lord of Destruction and then now the moment the sword was sheathed the boney exoskelton vanished as did the wings, the tail remained and Harry collapsed to his knees in exhaustion looking like a ratherly overcooked side of beef. Yugao grinned "I ordered him rare."

Harry chuckled and wheezed "The chef ballsed the order so you've got well done and please stop making laugh. He's buggered at least three ribs."

Yugao nodded "About the coffee...I'll accept. I think I'm going to need a deep discussion about a colleague going all demonic furnace on Astorath. Not that is wasn't appreciated."

Harry groaned "Got you..." He looked around at the assembled auror's "...Nothing to see here. Move along."

"Mr. Potter you're under arrest." Ordered an auror only to see Harry's tail grab the Sig Sauer and cock it.

"I think not...Paladin, what are they arresting me for?"

"Dark magic, abandoning the Wizarding World, illegal summoning of Djinn...And several other charges." Harry smirked coldly.

"Are you going to allow this to happen?"

"Nope. You are a comrade. One who has blood of our enemies but an..."  
"Ally is an Ally. Are you liable to get involved if things get exciting?"

"Only if they instigate."

Harry turned to the auror's "I politely decline the arrest...For I all I know your boss could be making up false charges."

With that the world went silent, Rin had just managed to beat Amaimon with Mephisto's interference. Everyone looked at the auror and Harry armed with two blades and his tail holding his gun.


	9. Chapter 9

Aka no Ex  
Red Exorcist  
Blue Exorcist/Harry Potter crossover

 **Darksider82  
Anyone**

 **Neun: One Of Them Days**

"Harry stand down. We can resolve this peacefully." Angel said stepping between his irate cousin and the twitchy auror's. Harry slowly sheathed his swords and lowered his gun causing Arthur to give him a quick nod and a grin before stepping aside to let the auror's holster their wands but that was not the case.

"Stupefy! Expelliarmus! Incarcerous!" Shouted several auror's "Paladin! You..." Arthur turned to the aurors and raised Caliburn and effortlessly shattered the bindings on Harry, waved his hand and Harry scrambled to his feet, Harry grabbed his bag and pulled two sphere's into his hand.

"You people and your laws and your silly little spells. Did you think that they would protect you from me?" Harry growled as his magic literally began to pour off him.

In his collossal rage everyone felt the ground begin to tremble and in some places crack under strain of Harry's immense magical power. The auror's readied their wands. Harry grinned as he was preparing to fight for his groups continued existance when multiple loud bangs echoed around the square followed by the unmistakable bark of a shotgun which turned into chirps. "Who was the idiot with the shotgun?" One of the senior Dragoons asked rhetorically looking at one of the exwires.

Bon grinned sheepishly "I thought they were demons." Harry stared at him "Do you clearly not listen to the briefings." Harry said turning his back on the auror's "Yugao-chan if any of them do anything you think is remotely stupid drop them and hard." Yugao nodded and grabbed Harry's uncursed blade.

Dumbledore looked at the assembled Japanese Exorcists and revealed his pin. It was the exact same as Mephisto's execept it had the sigil of the British Exorcists. The British Exorcists were much more lenient in their punishments, due to the amount of fire elemantals in the country they trusted elemental exorcists to watch their own for any blue flames compared to the Japanese who were more Knights and Tamers. "It's good to see you Harry-san."

"Dumbledore-Shishou. It is good to see you again. You asked for us and we came as quickly as possible. What is it?" Harry asked curiously.

"Voldemort has returned openly we both knew he would but what troubles me is that he has been in the company elements of the kin of Fire, Spirits and Water that is confirmed and rumoured Light Kin as well."

Harry groaned "Iblis, Azazeal, Egyn and possibly Lucifer! Why couldn't you have asked us to come on a cleansing mission...that'd be easier." Harry growled his eyes flickering purple red. The dialogue was stopped when another series of bangs erupted this time to Yugao's back.

"What is going on here! Arrest them aurors!" Shrieked Fudge who squealed like a stuck pig as Harry casually shot Fudge's hat off his head and said bullet also split an abandoned banana split the first was to show his accuracy and the second well Harry would later on say he just got lucky but really Bartimeaus decided to be helpful before dispelling.

"Auror's arrest them." Demanded Fudge his finger jerking "Hello to you to Minister...Really throwing your toys out of the pram because we came to clean up your mess." Harry growled. Harry had a growth spurt during his time in Japan, whereas before he was an inch or two taller than the Minister he was now a good four to seven inches taller with no sign of slowing down yet.

"Mr. Potter, I don't like..." Began the Minister.

"That I'm insinuating in front of a Japanese Delegation of aware mundanes and magicals of the British Magical World and Exorcists that we're inept and corrupt. Yes I am...I'm here Fudge because I have orders. Orders given to me by a competent senior officer who gave me REASON to be here not because of lineage." Harry growled his tail lashing and looping around his sword.

"I can assure Mr. Potter that..." Blustered Fudge only for him to cut off by a woman that at close range, Harry was certain Son of Satan in Human Form he may be but this woman would have no problem giving him a kicking that he would remember for days if not weeks.

"The Minister is trying to make you feel like you have wasted your time. Riddle attacked me at my home. It was only due to the Wards of the Bones House that save my life." Harry's eyes narrowed at the Minister idly wondering if he could kill the Minister and pass it off as a heart attack.

"Don't...Just don't." Yugao told him looking him flat in the eye pulling out a water sphere and muttering a spell in Hebrew. Hebrew wasn't Harry's best language but he knew the spell had turned the water into an irritant. "Fine Yugao-san. I won't use the Minister as a ragdoll."

Harry turned to the assembled Ministry officials who were looking at the situation in dissaray "It's going to be one of them days. Paladin-san the painkillers are on you."


	10. Chapter 10

Aka no Ex  
Red Exorcist  
Blue Exorcist/Harry Potter crossover

 **Darksider82  
Anyone**

 **Zehn: Back to Hogwarts**

Harry and the Exorcists managed to extricate themselves from Diagon Alley. After crashing at some undisclosed location *Grimmauld Place* where they had to endure the loud and embellished mother hen of Molly Weasley. Yugao grabbing Harry's swords with Yukio grabbing his brothers guns to stop him from killing Snape.

Needless to say it was an entertaining couple of days. Finally the exorcists were being escorted by several members of the Order of the Phoenix to the trainstation. It was understandable the exorcists weren't above not taking people alive whereas The Order wanted people to repent.

The trip from Grimmauld to the Train was simple enough. The train ride was uneventful aside from Malfoy trying to be an obnoxious prat but that was by the by. Harry this time had a feeling he'd enjoy Hogwarts this time as he stretched out. Hermione and Ron jumped when they heard Harry's limbs crack and pop due to the cramped space. "Settle down Harry." Called Yugao who was disgruntled as she was resting her head on his shoulder. She may be his superior but she was also close to him in age and thus allowed to break protocol.

Everyone arrived at Hogwarts, Harry piled into the carriages with Ron and Hermione and fell asleep again stowing a handgun and sword inside his trenchcoat along with various other tricks such as a quick summoning circle keyed to his four djinn and his 'Exorcist Approved' summons list.

"We're here Harry." Hermione called, she couldn't help but snort as Harry fell out of the carriage, picked himself up and trudged inside. As he entered the hall a smile crossed his face as he saw Shura, Arthur and Mephisto sitting at the table. "Exwire Potter...We're going to be using you as part of our class teaching." Stated Shura, her hand drifting to her tattoo.

Harry grinned "I accept." With that he bowed with an elaborate hand gesture before getting shooing dismissal from Arthur which he retaliated with a flip off. "How can I be related to a teen like you?" Arthur asked aloud. "Because of the Lord Almighty and Birds and the Bee's. Besides you know how my mother was supposedly and her sister." Arthur nodded "Yes...I can't fault here. I dislike that you're demon born."

Harry smirked "I don't. But be greatful that my fate is tied up in something else." Arthur chuckled "Yes, our destructable and immortal shock trooper. What happened in the Alley to cause you to lose your humanity?"

"Demon Lords, Amaimon and Astaroth. I fought Astorath, got kicked around. Yugao joined in and got kicked around. He was about to start eating civilians and Yugao held my powers lock and key and I asked her to make a decision of allowing my true self become shown at the risk of hundreds of lives. If you execute me know this, I'll make the same mistakes again and again."

Their dialogue had caught the attention of the students and few began to step back as smoke began to trickle out of Harry's fingertips. Mephisto tapped his umbrella sharply "Arthur, stop testing him. He's brash and stupid true. But do not doubt what he did. Yes he's a demon but he's got a human heart. Even you can see the humour in it." Arthur nodded.

Harry sat down "What was that about demanded Hermione?"

Harry stared at her "Complicated...Very complicated." Hermione sniffed sharply "Uncomplicated it." Harry shook his head "You'll get all indignant and start barking up the wrong trees and making things harder for me." Hermione's eyes glistened "I only..."

During their discussion Shura Kirigakure made her way over to them "You two..." She said gesturing to Hermione and Ron "...Must be his mates...This is way out of everyones hands including our illoustrious paladins. Anyways all of you eat up and then you're going to have a practical demonstration on some of the new classes you're going to be having."

Dinner was an interesting affair as Dumbledore had publically sorted all of the exorcists who were seventeen or under into houses. Yugao had been sorted into Gryffindor and immediately grabbed a seat next to Harry much to Ginny's chagrin. "He's mine Ginny-san." Then Dumbledore stood up.

"Students, in light of recent events. Hogwarts is going to be playing host to a large squad of Exorcists from Japan and Britain. With persuasion from the Grigori Counsel, who have concented that the population of Hogwarts will learn from them and should they have potential or willing to try and become an Exorcist. But first a demonstration and therefore I hand over to the Paladin, His Holiness, Arthur. A. Angel of the Class 1979."

Arthur stood up "Thankyou Headmaster Dumbledore. Exwire Potter and Second Class Exorcist Hyuga please stand and display the Meister Role of the Knight."

Harry and Yugao pulled off the robes, leaving Harry in a baggy jumper and combat trousers and trainers. "Not fighting in a vest?" Harry grinned "Not willing to burn my jumper or reveal my full powers but needless to say I may display some other skills." He said as he drew his Chokuto. Yugao drew her broadsword and the pair crossed blades and the duel began.

The students were transfixed as the duo clashed blades and exchanged; punches, kicks and flips along with sword exchanges at lightning speeds. The students were transfixed, transfixed so much that they couldn't gasp when Harry kicked Yugao in the leg sending her off balance only for her to reverse it with a resounding kick to the ribs.

Arthur nodded at Harry causing him to grin "Bartimaeus! Hearken!" There was a flash of heat and something appeared. Yugao jumped backwards pulling out a handgun and with amazing dexterity shot a pentagram around Harry's feet. "These two have so far demonstrated the Meisteries of a Knight, Tamer and Dragoon. Or Swords, Summoning and Gunplay. Our other Meisters are Aria's or Preachers and Doctors our Medics. You two are dismissed."

Harry shook himself down "Really? Shooting my feet." Yugao smirked at him "You're the one who told me if you need to shoot a knight take his feet." She replied impishly. Harry hit his head on the table "It's his legs or knees, never the feet."

Hermione stared at Bartimaeus in shock "Is that a Demon." She exclaimed, Harry looked at Bartimaeus who nodded and dissappeared in a plume of smoke "Djinn actually. Find the term Demon insulting. Had to pull one off my colleague because he used one MY summonings." Harry grinned as Hermione looked poleaxed "Explain." She demanded.

Harry, and the Muggleborns nearby dissolved into giggles as it came out high pitched and robotic. Harry couldn't help but laugh as he pictured Hermione in a Triangular and Spherical for the better term Dustbin with a whisk and a plunger or for those in the know; Dalek. "What's so funny." Screeched Hermione causing even more laughs. "You...sound...like...a...Dalek." Harry waved his wand and muttered something under his breath.

Hermione stared at Harry with flames in her eyes "I didn't do this. Anyways hysterics aside. Two sorts of summons. Magician summons and Exorcist summons. I don't know the difference as I use Magician Summons. Anyways from the words of the Djinn itself; Five generic categories of Mariads, Afrits, Djinn, Foliots and Imps however more that can't be classed as Imps and some cannot be classed as Mariads. They and Magicians look at things called the Planes. The stronger the Spirit...Preferred calling the more Planes they can disguise themselves on. However according to Bartimaeus if you use more than eight planes then you're a show off."

Hermione had her quill out and was scribbling away as were everyone else who were interested. Apparently Mephisto had slapped him with a microphone powered by his own magic and he was talking to the whole school. "What are they made of?" Asked a Ravenclaw Seventh Year.

Harry spun on him "How can you hear me?" The Ravenclaw pointed to Harry's ear and Harry saw the microphone and a grinning Mephisto and smirking Arthur "Bloody pranksters for superiors. I'll get them...somehow...Anyways they're made up of Essence that comes from the Otherside. That's all I know at this moment in time."

"How do you control them?" Asked Terry Boot. "Carefully. Very carefully. Word of Advice unless you're suficiently skilled in protections use an alias. Unfortunately for me I can't...Not with the ones I call on. Family bound. As for Bartimaeus he's the only one that has the best mix of Spirit-Human relationships, has something akin to diplomacy, brains and can throw around a fair few spells. The others I have are all of one none of the rest. One is according to Bartimaeus 'Seriously lacking in intelligence but is moronically strong to the point of indestructability.'"

"You mentioned entities that are 'Beyond the Classes', how would you Harry deal with them? I mean if the rumours are true you've faced a Troll, Killed a Snake of somesort, driven off Dementors, outwitted a Dragon, the Denizens of the Lake and duelled You-Know-Who...Can you clarify the others if you can."

Harry grinned "Stuck my wand in the Troll's nose and piggybacked it. Ron dropped the club on the Trollshead via leviation, First Year. Basilisk, it's in the Chamber of secrets. I'll take tours of year groups if teachers permit. Yes its true a Patronus. Grindylow, Merfolk, Redcappers and that's it won't say how as that will open me to libel and being an accomplice. Duelled Voldemort true but can't say all those times I had no way out. But for these things RUN. Run you clever children and remember. They manipulate WARP REALITY at its FUNDAMENTAL LEVELS. Our laws moth magical and muggle views on physics are gone the moment they show up. So RUN. If you think of summoning one I'll put you against the wall and kill you myself." He finished with a growl.

"On a more pleasent note, off to bed and remember classes start after the weekend." Announced Dumbledore.


	11. Hiatus

Hiatus of a possible permanent basis.

I'm sorry to type this but due to many other obligations and possible permanent writers block this story has been put on hold. Feel free to take it and re-work it.


End file.
